Unseasonably Mild and Dry: November and Fall 2015 Recaps

Dr. David A. RobinsonNew Jersey State ClimatologistCenter for Environmental Prediction, School of Environmental and Biological
Sciences/NJAES, Rutgers UniversityDecember 4, 2015

November Overview

The climatological fall season ended on a mild note, with the statewide November average temperature of 49.3° coming in at 3.7° above normal. This ranks as the 5th mildest November on record, tied with 1948 (Table 1). Observations go back 121 years to 1895, yet five of the nine warmest Novembers have occurred since 2001.

Rank

Year

Nov. Avg. Temp.

1

2006

49.9°

2

1975

49.6°

2

2009

49.6°

4

1931

49.5°

5

2015

49.3°

5

1948

49.3°

7

1994

49.2°

7

2001

49.2°

7

2011

49.2°

10

1985

49.0°

10

1999

49.0°

Table 1. Top 11 warmest NJ Novembers since 1895.

The month had an abundance of sunny days, during what is commonly a rather cloudy time of the year. Precipitation averaged 2.33” across NJ, which is 1.31” below normal and ranks as the 41st driest November. Only two significant rain events occurred during the mid-month interval.

Temperature

Maximum temperatures topped out at 65° or higher on 15 November days at one or more of the 56 NJ Weather and Climate Network stations. A seven-day run of such highs began on the 1st when Cape May Court House (Cape May County) and Egg Harbor Township (Atlantic) each reached 68°. Seven stations made it to 65° and 15 stations to 64° on the 2nd. Haworth (Bergen) topped out at 79° and Hawthorne (Passaic) and Walpack (Sussex) at 78° on the 3rd. Walpack began the 3rd with a low of 31°, the daily minimum in the state, resulting in an impressive 47° diurnal temperature range at this northwest Jersey valley location. The 4th saw Cherry Hill (Camden), Sewell (Gloucester), and South Harrison (Gloucester) up to 79°. Toms River (Ocean) reached 75° and five stations 74° on the 5th. The 6th rivaled the 4th as the warmest November day, with four stations up to 77° and 53 other stations between 70°–76°. Only five locations remained at 68° or 69°. The week-long run ended on the 7th with Hillsborough (Somerset) at 73° and Jersey City (Hudson) 71°. An interesting aspect of this week was how the warmest daily maximums shifted from one portion of the state to another on a daily basis.

Mansfield (Burlington) was 65° on the 11th and Cherry Hill and Sicklerville (Camden) 71° on the 16th. West Cape May (Cape May) reached 65° on the 18th, and eight stations got to 67° on the 19th, with 18 others at 65° or 66°. Sea Girt (Monmouth) led the way with 66° on the 20th. A three-day run of warmth began on the 26th with Woodbine (Cape May) up to 68° and Dennis (Cape May) and Piney Hollow (Gloucester) each 67°. West Creek (Ocean) got to 69° on the 27th, with 29 locations between 66°–68° and only High Point Monument (Sussex), with a maximum of 58°, remaining below 60°. Egg Harbor Township reached 69° on the 28th, with six stations at 66°.

There was not a complete absence of cold air during November. Minimum temperatures on 12 days were at or below 25° at one or more station. As usual, Walpack was among the coldest locations. Starting on the 9th at 21°, this station was the coldest on each of those 12 days. The 15th found Walpack at 23° and Pequest (Warren) at 24°. Walpack was 23° on the 17th and 22° on the 18th when Pequest was 25°. Walpack was 24° on the 20th and 22° on the 21st when Pequest was 23°.

The 23rd found daily minimums occurring in the late evening with Walpack and Kingwood (Hunterdon) dropping to 17° and Pequest to 18°. That evening found Harvey Cedars (Ocean) and Seaside Heights (Ocean) reaching the freezing mark for the first time this season. Temperatures fell until dawn, when Walpack reached 15°, and Kingwood, Berkeley Township (Ocean), and Pequest got down to 16°. West Cape May fell to 28° on the 24th, the first sub-freezing minimum of the season at that location. This left Atlantic City Marina (Atlantic), which reached 33° late on the 23rd and the morning of the 24th, as the only NJWxNet station not to reach the freezing point through the end of November. The cold continued on the 25th, with Walpack at 18° and Berkeley Township 19°. Walpack was 20° and Basking Ridge (Somerset) 21° on the 26th. The last two days of the month saw Walpack at 22° and High Point Monument 25° on the 29th and Walpack 15° and Pequest 19° on the 30th.

With the growing season, defined as the number of consecutive days when the minimum temperature remains above the freezing mark, having ended at all but Atlantic City Marina, it is interesting to take a look at range of season length across Garden State. The 2015 season was as short as 145 days at Walpack (May 25th – October 16th) and as long as 246 days and counting at Atlantic City Marina (March 30th – November 30th). This 101-day difference tends to be par with recent years. Stay tuned for the December report to see when the season might end at the Marina. Other notable short seasons included Pequest at 154 days, Berkeley Township 167 days, and Basking Ridge 168 days. Harvey Cedars and West Cape May each had lengthy 238-day seasons.

Precipitation and storms

Southern coastal locations were the wettest in the state during November. Stafford Township (Ocean) topped the list with three CoCoRaHS stations measuring 4.26”, 3.87”, and 3.84”. Other stations with some of the largest totals, which climatologically speaking were only just above the statewide long-term November average of 3.64”, included Woodbine at 3.91”, Ocean City (Cape May) 3.89”, Egg Harbor Township 3.88”, and Wildwood Crest (Cape May) 3.81”. Central areas tended to be driest, with Bridgewater (Somerset) receiving only 1.49”, Cranford (Union), Edison (Middlesex) and Woodbridge (Middlesex) each seeing 1.51”, and New Brunswick (Middlesex) 1.53”.

The first rain of the month that exceeded 0.10” occurred in the southeast during the afternoon and evening of the 7th. Woodbine and Middle Township (Cape May) received 0.35” and 0.30”, respectively. No measurable rain fell north of the Atlantic City Expressway. The first of two mid-month soaking events began during the predawn hours of the 10th and lasted approximately 24 hours. Wildwood Crest received 2.73”, two Stafford Township stations saw 2.72” and 2.54”, Pine Beach (Ocean) picked up 2.36”, and Ocean City 2.35”. The heaviest of the rain was not especially widespread, as just 20 of the 217 CoCo reports exceeded 2.00”, while 51 were between 1.00”–1.99”. On the low end, Kearny (Hudson) saw 0.23”, North Arlington (Bergen) 0.24”, and Bridgewater 0.25”.

The second heavy event of the month occurred from midday to late evening on the 19th. Randolph Township (Morris) received 1.94”, and 122 of the 220 CoCoRaHS reports exceeded 1.00”. New Providence (Union) had 1.90”, and Chatham (Morris) and Denville (Morris) each received 1.86”. Overall, Morris County caught more than 1.50”, the rest of northern half NJ and portions of the coastal counties 1.00”–1.50”, while the least rain, in the 0.40”–0.60” range, fell in the southwest.

Precipitation was sparse to nonexistent from the 20th until the 29th when light morning rain fell in the far south. Two Upper Township (Cape May) stations measured 0.35” and 0.34”, with 0.34” in Woodbine. Less than 0.10” fell most everywhere else in NJ.

No measureable snow fell in NJ during November. In fact flurries fell in only a few locations on the 22nd and 23rd.

The lowest atmospheric pressure readings of November were observed on the 12th, ranging between 29.50”–29.60”. One of the strongest high pressure systems in recent years invaded NJ on the 25th, with maximum values early on the 26th between 30.80”–30.85”.

Winds gusted to 40 mph or higher at one or more NJWxNet stations on five November days. Harvey Cedars reached 41 mph on the 10th. The 13th was the windiest day of the month. Wantage reached 53 mph, and High Point Monument 49 mph. Four stations gusted from 40 mph to 43 mph and maximum gusts were between 30 mph to 39 mph at 23 stations. The 14th saw maximum gusts of 49 mph at High Point Monument and 42 mph in Harvey Cedars. Stewartsville gusted to 43 mph on the 19th and High Point Monument to 46 mph on the 20th.

Fall Overview

With September the 3rd warmest on record, October around a half degree below average, and November the 5th mildest, it is no surprise that the season as a whole averaged on the warm side. The 58.1° average was 2.6° above normal and ranks as the 5th warmest fall on record (Table 2).

Rank

Year

Fall Avg. Temp.

1

1931

59.1°

2

2005

58.5°

3

2007

58.2°

3

2011

58.2°

5

2015

58.1°

6

1961

58.0°

7

1900

57.9°

7

1946

57.9°

9

1985

57.7°

10

1941

57.4°

Table 2. Top 10 warmest NJ falls since 1895.

September rainfall was 0.43” below average and October 0.32” above, just about balancing things out for these two months. Thus it was November’s 1.31” negative anomaly that produced the bulk of the 1.42” seasonal negative departure. Fall precipitation totaled 10.22”, which made for the 56th driest on record.

A key characteristic of fall 2015 precipitation was the small number of moderate to heavy rainfall episodes separated by many days of quite dry conditions. This followed a similar pattern in mid to late summer. It was dry enough for the northeast corner of the state to fall into “moderate drought” on the US Drought Monitor map in September. The region remained in that category through the rest of the fall. “Abnormally dry” conditions were depicted on the map for surrounding areas, and for a short time dipped into the south. Meanwhile the NJ Department of Environmental Protection’s Northeast, Central, and Coastal North water supply regions entered a drought watch on September 23rd and remained at that status for the remainder of the fall. Fortunately the rainfall was enough to prevent the state from falling further into drought, with the winter precipitation hopefully abundant enough to raise ground water, stream flow, and reservoirs by the time spring and summer 2016 arrive.